Vibrator for foundry molding and like machines

ABSTRACT

A vibrator for foundry molding machines which includes a through bore in the table or pattern stool or other part to be vibrated of the machine, a sleeve in the through bore, end caps threadedly engaged with the sleeve and bearing on the ends of the through bore to stress the sleeve, a ram in the sleeve, and sound attenuating inserts in the cap to reduce the noise level of the vibrator.

United States Patent Blower et al.

1451 Feb. 27, 1973 s41 VIBRATOR FOR FOUNDRY MOLDIN 1,940,388 12 1933 Callahan ..91 234 AND LIKE MACHINES 2,884,901 5/1959 Chandler ..259/72 x [75] Inventors: $322: ghg xg ia gfi g g Primary Examiner-Robert W. Jenkins Attorney-Oberlin, Maky, Donnelly & Renner [73] Assignee: The Sherwin-Williams Company,

Cleveland, Ohio 57 ABSTRACT [22] Filed: Aprils 1971 A vibrator for foundry molding machines which in- 21 APP] 131 099 cludes a through bore in the table or pattern stool or other part to be vibrated of the machine, a sleeve in U S Cl 259/1 259/1310 43 the through bore, end caps threadedly engaged with 51 lllt. Cl. ....B0lf 11/00 the sleeve and bearing ends the hmugh bore f Search 72, t0 SU'CSS the sleeve, a ram lll the sleeve, and sound at- 91/233 232 235 tenuating inserts in the cap to reduce the noise level of the vibrator [56] References Cited UNITED STATES PATENTS 9 Claims, 3 Drawing Figures 1,486,486 3/1924 Gates ..9l/234 Y 'JL -TJT; ,"|L 1\T *mht? i *F I WEE 121W T T r' T YTFH" i 111111 11 51 a g i 1 T 11: =1=1l1i l eflfii 111 3121 l l l ll l H' C444,, 1 28 ii '1 \il'm 17 01:11am a I .1:111:1 h a T J a; .5111; I 1 C ajl h 1 l 1' 1 l I I I l i I2 49 3O 20 3| ll 5| l9 Pmmwrm 3,718,318

INVENTORS.

WARREN A. BLOWER EM/L I? JERSE QMMJMJM ATTORNEYS VIBRATOR FOR FOUNDRY MOLDING AND LIKE MACHINES I This invention relates generally as indicated to a vibrator for foundry molding and like machines and more particularly to such vibrator having a longer life and reduced noise levels.

In foundry molding machines, vibrators are used on a number of machine parts to obtain, for example, sand flow or to assist in the draw of the pattern from the mold. Vibrators may be used on tables, pattern stools, matchplates hoppers and the like. Vibrators are normally fastened to the machine parts by suitable large fasteners with the end caps thereof held in place by tie bolts. Due to the nature of the vibrator as well as the nature of the machine environment they often shake loose of the machine, self-destruct as by shearing such tie bolts, and are noisy. Such characteristics are commonplace in prior art vibrators.

It is accordingly a principal object of the present invention to provide a vibrator which cannot shake loose of the machine.

Another principal object is a vibrator having a longer service life.

Still another principal object is a vibrator having markedly reduced noise levels well within acceptable ranges.

Yet another object is the provision of a foundry molding machine having a table or like part with a through bore therein in which the vibrator is secured.

Still another object is a vibrator of the type noted having end caps connected to a sleeve, the caps bearing against the ends of the though bore to stress the sleeve.

It is also an object to provide a stress sleeve vibrator wherein the sleeve is relieved along portions of its length to prevent stress concentrations.

Finally, a most important object is the provision of such vibrator having urethane or like inserts in the end caps to provide sound suppression.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed.

In said annexed drawing:

FIG. 1 is a fragmentary top plan view of a foundry molding machine table incorporating a vibrator in accordance with the present invention;

FIG. 2 is a vertical section taken substantially on the line 22 of FIG. 1; and

FIG. 3 is an exploded view of the end cap and insert partially broken away and in section.

Referring first to FIGS. 1 and 2, there is illustrated a foundry molding machine table indicated generally at having a lateral projection 11 with through bore 12 therein. For a more complete disclosure of a foundry molding machine table, reference may be had to the copending application of Edward D. Abraham entitled Jolt Squeeze Molding Machine, Ser. No. 860,381, filed Sept. 23, 1969, now US. Pat. No. 3,658,118. The end faces 13 and 14 of the projection 11 are finished and are at right angles to the axis of the through bore.

A vibrator shown generally at 16 is mounted in the through bore and includes four major components which are: end cap subassemblies 17 and 18; sleeve 19; and ram 20.

The cylindrical sleeve 19 is of a normal length slightly less than the length of the through bore and is provided with internal threads at each end adapted to engage the threads indicated at 22 and 23 on the axial extensions of the end cap sub-assemblies 17 and 18. The major part of the ID. of the sleeve 19 includes a finished surface 24 within which the ram 20 moves back and forth. The CD. of the sleeve is provided with a relatively shallow annular groove 25 connected by a plurality of exhaust ports 26 to the interior of the sleeve. A similar groove and exhaust port system shown at 27 and 28 is provided at the opposite end of the sleeve. Axially inwardly of the exhaust grooves 25 and 27 are O-ring seals 30 and 31. Between such O-ring seals, the CD. of the sleeve is relieved as indicated at 32 and 33 and between such relieved portions there is provided a pressure port 35 communicating with the interior of the sleeve. When forming the pressure port, the drill also forms a recess 36 on the axial opposite wall to provide a pressure balance to inhibit minor deflections.

Exhaust grooves 25 and 27 communicate with exhaust ports 38 and 39 in the table projection 11 while the pressure port 35 is in communication with air pressure hose 40 through the coupling indicated at 4!. The ram 20 is essentially a cylindrical slug having axial end projections 43 and 44. The ram is also provided with symmetrically arranged annular grooves 45and 46, each in communication with the opposite end of the ram through the respective axial passages seen at 47 and 48. A compression spring 49 extends between the end cap subassembly 17 and the ram maintaining the ram in the position seen in FIG. 2 when the vibrator is inoperative.

Referring now to FIG. 3, it will be seen that each end cap subassembly 17 or 18 includes the end cap and a resilient insert seen at 51. The end cap includes a hex head 52, the inside of which is provided with a finished face 53 adapted to bear against the end walls 13 or 14 of the projection 11 of the table. The shank of the end cap is provided with the threads 22 on the OD. and the interior of the shank is provided with a cylindrical recess 54. The cylindrical recess accommodates the insert 51 in a snug fit so that the insert may readily be manually inserted in the recess. Both ends of the insert 51 are chamfered with the longer chamfer 55 projecting from the cap when the insert is inserted. The insert is provided with a longitudinally extending saw slot seen at 56 to facilitate insertion and removal. The preferred material of the insert is polyurethane having a durometer hardness on the shore-A scale of from about to about and preferably about 90. It will also be appreciated that instead of utilizing the insert 51 in a metallic cap 17 that the entire cap may be onepiece made of the noted polyurethane.

In assembly, the sleeve with the ram and spring therein are inserted in the through bore and the end caps assembled with the inserts are then threaded into the ends of the sleeve. The end caps are tightened to approximately 500 ft/lbs. of tightening torque which will then stress or tension the sleeve actually stretching the same. In order to avoid improper stress concentrations, care is preferably taken to ensure that the crosssectional area of the sleeve through the relieved portions 32 and 33 is the smallest. Thus such relieved portions provide a uniform stretch area for the sleeve.

In operation, the vibrator is turned on by supplying air pressure to the vibrator through the hose 40. In the of position seen in FIG. 2, air pressure will enter through the port 35 and into the annular groove 45 supplying air pressure to the chamber at the right end of the ram through the axial passage 47. This causes the ram to move to the left against the pressure of the spring 49. Continued axial movement of the ram to the left will uncover the exhaust ports 28 in the sleeve and the pressure in the right end of the sleeve will then be exhausted to atmosphere through such ports, the annular groove 27 in the exhaust port 39. As the ram moves to the left as seen in FIG. 2, the pressure port shifts from communication with the groove 45 to communication with the groove 46 and when the latter occurs, pressure is supplied to the chamber at the left hand end of the ram through the axial passage 48. The ram then moves back to the right until the exhaust passages 26 are uncovered and the pressure in such chamber then exhausts to atmosphere through the passages 26, the annular groove 25 and the exhaust port 38. Continued air pressure will continually cause the ram to reciprocate striking the inserts in the end cap subassemblies l7 and 18. When the air pressure is turned off, the ram will assume again the position seen in FIG. 2.

With the inserts in the end caps as seen in FIG. 3, it has been found that the noise level of the vibrator is markedly reduced and is well within acceptable levels. Furthermore, the tensioning of the sleeve through the tightening of the end caps provides a longer wearing vibrator since the impact of the ram against an end cap assembly is transmitted through the sleeve to the opposite face of the projection 11 in which the through bore 12 is situated. The end cap inserts also contribute, of course, to the increased life of the unit. Finally, the mounting of the vibrator in the through bore not only facilitates the noted tightening of the end caps and thus the tensioning of the sleeve, but also precludes the vibrator from being shaken from the machine. The end caps can be tightened to the predetermined torque and then locked in position.

It can now be seen that there is provided an improved vibrator which cannot shake loose of the machine and which has a much longer service life. Moreover, a vibrator is provided having markedly reduced noise levels.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A foundry molding machine comprising a table or like part, a through bore in said part, end caps closing the ends of said through bore, a reciprocable ram in said bore operative to strike said end caps to .vibrate said part, a sleeve in said bore, said end caps being threadedly connected to said sleeve and bearing against said part whereby tightening of said end caps will tension said sleeve, pressure and exhaust ports in said part, pressure and exhaust ports in said sleeve, and annular grooves on the CD. of said sleeve corresponding to said ports.

2. A machine as set forth in claim 1 including seal means in the CD. of said sleeve between the pressure and exhaust grooves.

3. A vibrator comprising a housing, a sleeve in said housing, end caps connected to said sleeve and bearing on said housing to stress said sleeve, a ram in said sleeve operative to strike said caps to obtain vibration, pressure and exhaust ports in said housing, pressure and exhaust ports in said sleeve, and annular grooves on the CD. of said sleeve corresponding to said ports.

4. A foundry molding machine comprising a table or like part, a through bore in said part, a sleeve in said bore, end caps threadedly connected to said sleeve closing the ends thereof and bearing against said part whereby tightening of said end caps will tension said sleeve, and a reciprocable ram in said sleeve operative to strike at least one of said end caps to vibrate said part.

5. A foundry molding machine as set forth in claim 4 including a relieved portion in said sleeve operative to avoid stress concentrations.

6. A machine as set forth in claim 4 including an insert in at least one of said end caps to receive the strike of said ram operative to suppress noise.

7. A machine as set forth in claim 6 wherein said insert is polyurethane having a durometer hardness of about on the shore-A scale.

8. A machine as set forth in claim 7 wherein said insert is recessed within said end cap.

9. A machine as set forth in claim 4 wherein said end caps include axial projections threadedly connected to the sleeve ID. at its ends, and heads bearing against said part. 

1. A foundry molding machine comprising a table or like part, a through bore in said part, end caps closing the ends of said through bore, a reciprocable ram in said bore operative to strike said end caps to vibrate said part, a sleeve in said bore, said end caps being threadedly connected to said sleeve and bearing against said part whereby tightening of said end caps will tension said sleeve, pressure and exhaust ports in said part, pressure and exhaust ports in said sleeve, and annular grooves on the O.D. of said sleeve corresponding to said ports.
 2. A machine as set forth in claim 1 including seal means in the O.D. of said sleeve between the pressure and exhaust grooves.
 3. A vibrator comprising a housing, a sleeve in said housing, end caps connected to said sleeve and bearing on said housing to stress said sleeve, a ram in said sleeve operative to strike said caps to obtain vibration, pressure and exhaust ports in said housing, pressure and exhaust ports in said sleeve, and annular grooves on the O.D. of said sleeve corresponding to said ports.
 4. A foundry molding machine comprising a table or like part, a through bore in said part, a sleeve in said bore, end caps threadedly connected to said sleeve closing the ends thereof and bearing against said part whereby tightening of said end caps will tension said sleeve, and a reciprocable ram in said sleeve operative to strike at least one of said end caps to vibrate said part.
 5. A foundry molding machine as set forth in claim 4 including a relieved portion in said sleeve operative to avoid stress concentrations.
 6. A machine as set forth in claim 4 including an insert in at least one of said end caps to receive the strike of said ram operative to suppress noise.
 7. A machine as set forth in claim 6 wherein said insert is polyurethane having a durometer hardness of about 90 on the shore-A scale.
 8. A machine as set forth in claim 7 wherein said insert is recessed within said end cap.
 9. A machine as set forth in claim 4 wherein said end caps include axial projections threadedly connected to the sleeve I.D. at its ends, and heads bearing against said part. 